Furnace attachment



April 2, 1929. J c, MILES 1,707,531

FURNACE ATTACHMENT I Filed May 6, 1926 gwwnto'o z'%zo abko'zmir PatentedApr. 2,192.9.

* UNITED STATES 1,701,531 PATENT OFFICE.

'. James 0. nuns, or CLEVELAND, oruo.

summon erracnmnnr.

Application filed my 6, 1926. Serial No. 107,017.

which is mounted within the inlet conduit to: the heating chamber,together withdampers which normally are'open when the fan is stop ed,but are adaptedto be closed when the an is in operation. Ordinarily,operation of the fan is only. required at relatively short periods inorder to start the circulation of air through the heating system. Duringsuch periods of operation it is advisable to increase the rate ofcombustion in order to obtain a greater degree of efficiency.

The preferred apparatus for accomplish- 2 ing the above objects isillustrated in the drawings wherein Fig. 1 is a side elevation partly insection of a hot air heating furnace with an inlet conduit and showing adevice embodying my invention attached to the v furnace; Fig. 2 is asection taken through part of the apparatus shown in Fig. 1 and on aplane indicated by the line 22, while Fig. 3 is a section taken throughmy device on a plane indicated by the line 3-3 in Fig. 2. I

In Fig. 1, I have shown a furnace 10 having a base 11 which provides anash pit an aheating chamber 12 which surrounds the furnace chamber. Theheating chamber has 0 an inlet conduit 13 which may lead to a window 14in the usual way. Disposed across the inlet conduit, between the heatingchamber and the window, I have shown a frame 15 which has a fan opening16 ad- 5 jacent the central portion, and a damper opening 17 on eachside of the fan opening. A motor driven fan 18 is disposed across thefan opening within the conduit while dampers 19 pivotally mounted to theframe are arranged to close the damper openings at predeterminedintervals. The arrangement of fan and dampers is such that the dampersare normally open when thefan isstopped so as toallow theunrestrictedflow of air but are adapted to be closed into the system so that allwhenever the fan-is set in motion,

of the air then enters the system only through the fan opening. Toincrease the rate of combustion in the furnace when the fan is inoperation and thereby to provide additional heat at a time when thedemand on the furnace is at a maximum, I make an opening 20 in the ashpit casing directly in alignment with the conduit 13. I then provide anauxiliary conduit 21 which is preferably bent as at 22 intermediate theends, and which has an. 'openlng 23 disposed directly in the path of airwhich enters the heating chamber when the fan 1s in operation. MoreoverI prov1de a damper 24 Which is pivotall mounted at 25 adjacent'the upperside of t e conduit and 1s adapted to be held by the action of gravityin the closed position, such as that indicated by the full lines in Fig.3. The damper is comparatively light in weight, however, and thereforeis adapted to be swung to open position, as indicated by the brokenlines 24: in Fig. 3, whenever the fan is in operation. The opening ofthe damper allows air from-the fan to pass through the conduit 21 and toenter the ash pit, and thereby to increase the rate of combustion withinthe furnace. This action occurs automatically whenever the fan isstarted and stops automatically whenever the fan is stopped.

The bent portion 22 provides a trap into which ash dust may collect whenthe grate is shaken, wherefore opening of the damper 24 will not behindered when the fan is started. Moreover, as soon as the damper is (1opened, then the current of air will immediately blow the collected ashdust out of the trap and into the ash pit thus making a self-cleansingattachment which functions in a satisfactory manner.

It may frequently be desirable to lock the damper in closed positionwhile the fan is in operation. To this end I have shown-a bar 30 whichextends through an opening in the side of the furnace chamber 12 andthrough another opening in the side of the conduit 21 directly beyondthe closed position of the damper. This bar may be slid, wheneverdesired, into the conduit as shown in Fig. 2'so as to prevent opening ofthe damper while the fan is-in operation. When it is desired to allowautomatic o ening of the damper, then the bar may he pulled downwardlyuntil a pin 31 in the bar strikes theinner side of the heating chamberwall. This amount of movement is sulficient to allow the inner end ofthe bar to clear the damper and at the same time to prevent it frombeing pulled out of engagement with the conduit.

An important advantage of my invention is the sim licity of constructionand the assurance oi satisfactory automatic operation; A furnaceequipped with my invention will have an increased capacity and operatingefliciency in that the production of available heat units willautomatically be increased in the furnace chamber, when the demand inthe heating system therefor is also increased.

Having thus described .my invention, I claim:

1. In a hot air heating furnace, the combination with a heating chamberhaving an inlet conduit leading thereto, an ash pit having an inletconduit extendlng in the same general direction as the first mentionedconduit but out of contact therewith, means within the first mentionedconduit for forcing air into the heating chamber, a damper pivotallymounted on the second named conduit adjacent the inlet end thereof, saiddamper bein disposed in the'path of said means and eing normally closedby the action ofgravity but adapted to o ened whenever said means is inoperation or allowing air to enter the ash pit, whereby air may beadmitted into the furnace in proportion to pneumatic pressure of saidmeans, said second named conduit having a trap between the ash pit andthe damper into which solid particles may collect, whereby the dampermay at all timesbe free to open whenever said means is in o .eration.

2. In a hot'air heating urnace having a furnace chamber and .a heatingchamber, the heating chamber having an air inlet conduit leadin thereto,a motor driven fan associated with the conduit for forcing air underpressure "into the heating chamber,

said fanbeing adapted when inoperation JAMES cl MILES. a

